This is a pretty easy question. In a sane world, yes, having sex is consent to becoming a parent. If you believe in abortion however, Caleb is right. If a woman has a right to an abortion, it means she has the right to opt out of motherhood even after tacitly consenting to it by consenting to sex. So men must have the same right.

This is as cut and dry as any issue can possibly get: Consent to sex includes consenting to the consequences of sex. However, if we allow women to opt out of the consequences, equality demands that we let men opt out as well.